The use of phosphorous-containing compounds for use in lubricant compositions is known. In particular, the phosphorous-containing compounds generally comprise linear alkyl chains. However, the problem with these compounds is that they are known to be thermally unstable at elevated temperatures in a fully formulated gear lubricant. A thermally unstable compound is more likely to prematurely decompose in the lubricant composition and would no longer provide a property, such as antiwear, to the lubricant composition.
Lubricant compositions, such as gear oils, typically are subjected to elevated temperatures and therefore it would be beneficial to provide a thermally stable compound that would not prematurely decompose at higher temperatures. A thermally stable compound would therefore remain in the lubricant composition for an extended period of time and provide the property, e.g., antiwear, to the composition over the extended period of time. What is needed is a compound that has the proper thermal stability to sustain its antiwear property.